EVIDENCE GROWS ON POSSIBLE LINK OF FIBERGLASS AND LUNG ILLNESSES

By PHILIP SHABECOFF, Special to the New York Times

Published: March 15, 1987

WASHINGTON, March 14—
Emerging evidence that fiberglass and other manufactured mineral fibers may cause lung cancer and other diseases is creating a sensitive, potentially far-reaching public health issue.

The evidence, although far from conclusive, is sending tremors through the fiber industry and Federal regulatory agencies. Industry officials, however, insist the evidence to date shows no health problem.

These synthetic fibers, already in wide use as building materials and insulation, in cars, furniture and packaging and for many other applications in a $3 billion-a-year industry, are increasingly being employed as substitutes for asbestos, a known cause of cancer and other serious illness.

Now, recent studies of the health histories of workers who make fiberglass, rock wool and ceramic fibers, as well as tests on laboratory animals, suggest that the substitutes themselves may pose a health threat, albeit one of still unknown and heavily debated dimensions.

The results of the studies, although inconclusive, have caused a flurry of activity in the industry. Manufacturers of the synthetic fibers have undertaken costly new studies on the health effects of their products and are consulting with Federal regulators.

If the fibers prove to be a serious health threat, it could result in loss of sales, expensive damage claims and extensive measures to reduce exposure among workers, and possibly the general public.

The studies that are generating the most concern were based on an examination of mortality records of workers in North America and Europe who produced synthetic mineral fibers and were first exposed to relatively low levels of airborne fibers at least 30 years earlier. Scientists who have reviewed the studies agree that these workers show a higher rate of lung cancer than normal.

Industry officials insist that the evidence about fiberglass and other synthetic mineral fibers is inconclusive and that it is just as likely that the worker deaths found in the studies were caused by other factors, such as smoking, exposure to cancer-causing chemicals and family history. They also said that even if the synthetic fibers did cause cancer, the exposure levels were so low that there would be no serious public health threat.

But within the past few months, the manufacturers of fiberglass and related products, including Owens/Corning Fiberglas, the Certainteed Corporation and the Manville Corporation, have revised technical data sheets required by the Occupational Safety and Health law to state that recent epidemiological studies have found that their products might cause lung cancer. Protection From Lawsuits

Spokesmen for these companies said the changes were made because of their policy of keeping the public informed and because it was the law. But they also conceded that it was necessary to protect themselves against possible future lawsuits.

Most of the more than a dozen scientists, public health officials and Federal regulators interviewed said that even if the evidence about synthetic fibers causing cancer proved correct, the country probably would not be facing another health disaster of the dimensions of the asbestos epidemic. The number of premature cancer deaths caused by asbestos is now estimated at 9,000 a year and rising.

Raymond Motley, a lawyer representing the Sheetmetal Workers International and other construction unions in litigation over asbestos injury claims, said a number of studies have shown that fiberglass causes diseases such as bronchitis and emphysema in workers that produce it, and he raised the possibility that the unions might sue the fiberglass makers.

Evidence about the dangers of asbestos began emerging in the 1930's, but no action was taken to protect the public until the 1970's, after many workers had already developed lung cancer and other diseases. Now exposure to asbestos is stringently regulated by the Federal Government, and the Environmental Protection Agency has proposed gradually eliminating virtually all uses of the mineral. Cancer and Fiber's Shape

Research published in 1977 by Dr. Mearl Stanton of the National Cancer Institute indicated that it was the size and shape of the fiber, rather than its physical properties, that determined if it was a cause of cancer and other problems. Long, very narrow fibers that could penetrate deeply into lung tissue and remain there, causing tumors, are the main cause of concern, according to this research. It did not matter if the fiber was made of a natural mineral such as asbestos, or a synthetic fiber such as fiberglass, the researchers said.

In recent years manufacturers of synthetic mineral fibers have been making them thinner to increase their insulating properties.

Dr. Irving J. Selikoff, the noted asbestos authority at Mount Sinai Hospital in New York, said that there were not enough data to make a definitive statement about the health effects of fiberglass but that ''some serious questions have to be asked because this is a terribly important problem.'' One major unanswered question, he said, involves the dangers to those who install and use products made of these fibers, as well as to the workers who make them. Fibers Virtually Unregulated